Telephone system



Sept. 6', 1938.

F. 'R. LAMBERTY TELEPHONE SY-STEM Filed Sept. 9', 1936 18 Sheets-Sheet lINVENTOR F R. LAMBERT) 6R 9 at m at Q at 3 9 1 at 2 at 1 2st 59m 5 at Sat mi 2 at m 6E 61 A 7'TORNEV Sept. 6, 1938.

, F. LAMBERTY TELEPHONE SYSTEM Filed Sept. 9-, 1956 18 Sheets-Sheet 2 Ekumzzou it Q a T it a I lNVE/VTOR E R. LAMBERT) WN 14 TTQR/VEV Sept. 6,1938. F. R. LAMBE'RTY 2,129,011

TELEPHONE SYSTEM Filed Sept. 9,- 1956 1a sheets-sheet s OFF/CE SWITCHFla. 4

PRIMARY TRUNK SWITCH INVENTOR E R. LAMBERT) B -WW Q ATTORNEY Sept. 6,1938.

-F. R. LAMBERTY TELEPHONE SYSTEM l8 Sheets-Sheet 4 Filed Sept. 9, 1936 mRik Rub KEDU QSW GEN INI/ENTOR By FRLAMBERTV WWM A T TORNE'V F/RSTSUPERV/SORV CONTROL CIRCUIT Sept; 1938. I F. R. LAMBERTY 2,129,011

TELEPHONE SYSTEM Filed Sept. 9, 1936 18 Sheets-Sheet 5 INVENTOR ER.LAMBER TV ATTORNEY TELEPHONE SYSTEM Filed Sept. 9, 1936 18 Sheets-Sheet 6 S TOR/N6 RELAYS FOR RING/N6 DIG/7' SUPERI/ISORK IN 5 N 70k FR.LAMBERT) Sept. 6, 1938. F. R. LAMBERTY- 2,129,011

TEPEPHONE SYSTEM Filed Sept. 9, 1936 18 Sheets-Sheet 7 )QECORDER INVENTOR E R. L AMBERTV A TT'FORNEV Sept. 6, 1938. F. R. LAMBERTY 2,129,011

TELEPHONE SYSTEM I Filed Sept. 9, 1956 1a Sheet s-Sheet 8 RECORDERINVENTOR U U I FR. LAMBERT) A 7' TORNEV Sept. 6, 1938. F. R. LAM-BERTY2,129,011

TELEPHONE SYSTEM Filed Sept. 9, 1956 18 Sheets-Sheet 9 Q u Q Q E Q:

INVENTOR f. R. LAMBERTV ,4 TTORNE V Sept. 6, 1938.

S TOR/N6 REL/l VS HUNDREDS DIG! T F. R. LAMBERTY TELEPHONE SYSTEM FiledSept. 9, 1936 STORING RELAYS TENS .D/

18 Sheets-Sheet 10 Byway F R. LAMBERT) ATTORNEY Sept. 6, 1938. F. R.LAMBERTY TELEPHONE SYSTEM Filed Sept. 9, 1936 18 Sheets-Sheet 1 1INVENTOR FR. LAMBERT) AITORNEV Sept. 6, 1938. F. R. LAMBTERITY 9 9TELEPHONE SYSTEM Filed Sept. 9, 1936 1 1s Sheets-Sheet 12 RR. ALLOTTER i//v|/5/v R F R. LAMBERT) A T TOR/V5) FIG. /3

Sept. 6, 1938.

F. R. LAMBERTY TELEPHONE SYSTEM Filed septa 9, 1936 18 Sheets-Sheet 13 PP P P P P lNVE/VTOR F R. LAMBERT) BV ATTORNEY Sept. 6, 1938. F. R.LAMBERTY Y 2,129,011

a TELEPHONE SYSTEM' Fiied Sept. 9, 1936 18 Sheets-Sheet 14 H6 5 CONTROLCIRCUIT /NVE)V7OR I ERLAMBERTV 47 70 IVEV Sept. 6, 1938. F. R. LAMBERTYY 2,129,011

TELEPHONE SYSTEM Filed Sept. 9, 1936 l8 Sheets-Sheet l5 7Nl/EA/TOR F R.LAMBERTV WWW ATTORNEY -.Sept. 6, 1938. F. R. LAMBERTY ,9 1

TELEPHONE SYSTEM F iled Sept. 9, 1936 18 Sheets-Sheet 1e nvvz/vra/a F R-LAMBERT) ATTORNEY Sept. 6, 1938. F. R. LAMBERTY 2,129,011

TELEP-HONE SYSTEM Filed Sept. 9, 1936 18 Sheets-Sheet 17 CIRCUIT ISTRECORDER CCT- INVENTOR E. R. LAMBERTV A TTORNEY Sept. 6, 1938. F. R.LAMBERTY 2,129,011

TELEPHONE SYSTEM Filed Sept. 9, 1956 18 Sheets-Sheet l3 TRUHKS 10 EACHEXCHANGE ONE PER RECORDER AND TRUNKS INVENTOR F R. LAMBERT) FIG. [9

A 7'TORN V Patented Sept. 6, 1938 UNITED STATES PATENT OFFIQE TELEPHONESYSTEM Application September 9, 1936, Serial No. 99,919

Claims.

This invention relates to telephone systems and particularly to smallcapacity systems.

An object of the invention is to provide improved and economicallyarranged small auto- 5 matic system using cross-bar switches forestablishing connections between subscribers lines and betweensubscribers lines and trunks.

Heretofore systems have been provided for establishing connectionsbetween subscribers lines and trunks over links in a single switch, asshown, for example, by the patent to Hinrichsen 1,567,265 of December29, 1925, and patent to Goodrum 1,515,674 of November 18, 1924. In thecopen-ding application of Bowne et al., Ser. No.

' 5 95,530, filed August 12, 1936, now Patent 2,104,449 of January 4,1938, a system has been shown in which connections may be establishedbetween subscribers lines over a switch and between trunks over anotherswitch.

20 A feature of the present invention is an arrangement in which theconnection between subscribers lines may be established through oneswitch over links, in which connections from subscribers lines to trunksmay be established over the same type of. links to another switch, andin which connections from trunks through subscribers lines may beestablished over the same type of links through said other switch.

Another feature of this invention is an arrangement whereby connectionsbetween subscribers lines may be established over links and 'a controlcircuit through one switch, whereby connections may be established fromsubscribers lines to trunks over the same type of links 5 throughanother switch with the temporary aid of a control circuit, and wherebyconnections may be established from trunks to subscribers lines over thesame type of links through said other switch with the temporary aid of acon- 10 trol circuit.

This invention has been illustrated in the accompanying drawings inwhich the circuits for a small dial office have been shown embodying thefeatures of the present invention.

45 Fig. 1 shows the arrangement of the figures for the reading of thecircuits;

Fig. 2 shows in diagrammatic form the general layout of the switches andcircuits;

Figs. 3 to 10 show details of the circuits of the 50 system;

Figs. 3, 4 and 5 show the cross-bar switches employed by two subscriberslines, two supervisory control circuits and two trunks circuitsterminating in these switches;

.55 Figs. 6 and 7 show circuits in detail of one supervisory controlcircuit;

Figs. 8 to 11 show the circuits of one recorder for recording callednumbers;

Fig. 12 shows the details of one of the trunk 1.60 circuits;

Fig. 13 shows an allotter circuit for the supervisory control circuitand the recorders;

Fig. 14 shows a recorder-connector cross-bar switch for connecting therecorder to the allotted supervisory control circuit when a call ismade;

While Figs. 15 to 19 show a common control circuit relay and circuitarrangement employed in establishing of connections.

Referring now to Fig. 2 the circuits may be arranged with the followingswitches: primary line switches PLS for connecting the subscribers linesto line link LL; secondary line switches SLS for connecting supervisorycontrol circuits such as SCC1, SCCz and S003 shown to line links LL;secondary trunk switches STS for connecting trunks to line links LL;(Three trunks have been shown) primary trunk switches PTS for connectingthe trunks to supervisory control circuits; oifice switches OS forconnecting trunks together in tandem connections; recorder-connectorswitches RC for connecting recorders R1 to Re, to supervisory controlcircuits during the establishing of connections.

Four types of connections may be made through these switches; calls fromone subscribers line to another, calls from a line to a trunk, callsincoming from a trunk to a subscribers line, and tandem calls from onetrunk to another.

A call may be made from a subscribers line A by the removal of thereceiver from the switchhook, through a primary line switch PLS at across connecting point 209 to a first line link LL to one branch, of afirst supervisory control circuit SCC1 at a cross-connecting point 26!.A recorder such as R1 is normally allotted so that when this connectionat point 2M is made a connection is made to this recorder through therecorder-connector switch RC from the seized supervisory controlcircuit. A subscriber then dials the desired number and when the numberhas been recorded in the recorder a selection is made in the secondaryline switch SLS to connect the outgoing branch of the supervisorycontrol circuit SCC1 through a cross-connecting point such as 293 toanother line link LL and to a called subscriber B through the primaryline switch PLS at a cross-connecting point such as 206. The recorder isthen released and the connection completed from subscriber A tosubscriber B through the supervisory control circuit SCC]. over the fourconnecting points 200 to 204.

If a connection is to be made from a line to a trunk, the subscriber atA, for example, establishes a connection through cross-connecting points2% and 291 to an idle supervisory control circuit and a recorder anddials the number of the desired exchange in which the trunk is located.Then connections are established over the same line link LL in thesecondary trunk switch STC, for example, at cross-connecting point 206to an idle trunk 201 outgoing to a distant exchange. When thisconnection is made the supervisory control circuit connected atcross-connecting point 20I is released and by the release of thesecondary line switch SLS so that the connection from subscriber A totrunk 201 now extends over the line link LL through the two connectingpoints 200 and 206.

If a connection is to be made from a trunk to a line for example, fromtrunk 201 to the subscriber at A, the trunk 201 is connected through theprimary trunk switch PTS to a supervisory control circuit such as $001at the cross-connecting point 209. The number is then dialed over thistrunk through the allotted recorder such as R1 and a connection is madeover the outgoing branch of the supervisory control circuit 8001 at thecross-connecting point 203 for example in the secondary line switch SLSto connect with an idle line link LL having access 'to the called line.Connections are then made at a cross-connecting point 204 in the primaryline switch PLS to the subscriber at B from line link LL and at across-connecting point 2I0 in the secondary trunk switch STS between thecalling trunk and the line link LL. The supervisory control circuit SCCiis released by the release of the secondary line switch SLS and theprimary trunk switch PTS at the points 203 and 209 as soon as the calledsubscriber answers the ringing and the talking connection is maintainedover points 204 and 2I0.

If a tandem trunk connection is to be made, for example from the trunk201 to trunk M I, trunk 201 seizes a supervisory control circuit and isconnected thereto at the point 209 in the primary trunk switch PTS andthe desired trunk connec tion is then dialed. A connection is therebymade over the supervisory control circuit to establish connections inthe 001cc switch OS to connect the incoming calling trunk 201 with acalled trunk 2II over a link in the ofiice switch as for example thecross-connecting points 2I2 and 2I3 over the link 2I4. When theseconnections are established the supervisory control circuit is releasedby the release of the primary trunk switch PTS. To establish aconnection from a recorder to a supervisory control circuit, connectionsare made at a number of cross-connecting points as the number of leadsbetween the recorder and the supervisory control circuit is quitenumerous and it will be noted that in the recorder-connector circuitshown in Fig. 14, there are eighteen leads for each recorder. Thisrequires three connecting points for each recorder to a supervisorycontrol circuit such as the points 2 I5, 2| 6 and 211 from the recorderR1 through the supervisory control circuit SCC1, with six leadsconnected up at each point, each group of six leads is symbolized by asingle vertical line through the crossbar switch.

Descriptions of these various calls will now be made in connection withFigs. 3 to 19.

It is now assumed that a call is made from the substation A tosubstation B. The subscriber at station A will lift his receiver fromthe switchhook and thus cause an idle supervisory control circuit, anidle line link, and a recorder to be seized and connected to the callingline. When a calling line is connected over a line link to a supervisorycontrol circuit, a dial tone is sent for the dialing. The lifting of thereceiver from the switchhook by the subscriber at A closes a circuit forthe operation of relay 300, from battery through the right-hand windingof this relay, contacts of the holding magnet 30I over the subscribersloop through the left-hand winding of relay 300, contacts of relay 30Ito ground. This relay in operating closes a connection to ground for theGRP and LT leads. The ground on the GRP lead closes a circuit for theoperation of relay I800 in the control circuit. This relay is associatedwith the subscribers group of ten lines in which the calling line A islocated and the circuits of this relay may be traced from battery,contacts of relays I80I, I802, I803 and I804, windings of relay I800,contacts of relay I805 over the GRP lead to ground at relay 300 overcontacts of relay 302. It will be noted that a set of relays such asI600, and I805 are provided for each group of ten lines, relays I800 andI805 being provided for the first group of ten lines. Similar relayssuch as I806 and I801 are provided for each group of ten trunks. Itshould be understood that similar relays are provided for other groupsof ten lines and ten trunks. For the sake of simplicity no other similarrelays have been shown in the circuit. In the same manner relays such asI MI and IBM are provided for each recorder. These two relays areprovided for the sixth recorder and relays I802 and I8 are provided forthe first recorder. When relay I 800 operates a circuit is closed forthe operation of relay I805 from battery through the windings of thisrelay, contacts of relay I800 through corre sponding contacts ofunoperated relays, not shown, between relays I800, and I805 throughcontacts of relays I806, I803, I804 to ground at relay I100. Relay I800locks to battery through its own armatures and front contacts, contactsof relay I805 to ground at release relay I102 independent of the groundon the GRP lead. Re-

lay I800 disconnects battery and ground from the armatures and contactsof the corresponding relays for other groups of ten lines so that relaysof higher numbered groups and lower numbered groups of ten lines cannotbe operated. Therefore but one relay such as I805 can operate at a time.Relay I805 closes a circuit for relays I900 and I600 in series over acircuit from battery through the winding of relay I600, winding of relayI900, contacts of relay I805 to ground. There is provided one of each ofthese relays I900, I600, I602, I603 and I604 hereinafter mentioned foreach line group. Relay I805 also connects leads 4 and 5 to the allottercircuit in Fig. 13 for the operation of the start relay II from batterythrough the windings of relay I10I, contacts of relays I100, I805, I300to ground at contacts of relay I30I. Relay I10I provides a lockingcircuit for itself through its windings and contacts of relay I100 toground at contacts of relay I10I. The operation of relay I600 closes anobvious circuit for relay I602 and also a circuit for relay I603 frombattery through the winding of this relay, contacts of relays I604, I600and I500 to ground. Of these relays I600, I602 and I603 associated withthe group of line switches in which the calling line appears, relay I603connects battery to the sleeves of the ten line links LL, and LLI andothers not shown in this group and causes the operation of relays IBMand I502 which represent the first and the last links in this group often, and other intermediate relays omitted. Now any line link that isbusy will have a ground on its sleeve from the supervisory controlcircuit and such of the relays as I50I or I502 which are connected tothis sleeve will not oper-

